Estimating the weight impact due to a variation of a design variable, particularly a material property, is a very common work performed in the design phase of an aircraft when the designer search for an optimized structure. Material improvements can drastically reduce the structural weight and, therefore, diminish the operating costs of the aircraft. Thus, the improvement of the mechanical properties of the manufacturing materials of aircrafts, particularly composite materials, is a permanent goal for aircraft manufacturers. In fact, huge amounts of money are invested in material research.
However, material improvements will not necessary lead to significant weight reductions. The final weight of a component is the addition of its structural weight and its non-structural weight. The structural weight is driven by the final thickness of its structural elements. From one side, this thickness is related to the structural failures cases that are driven by the material properties, but they are also driven by other requirements that are independent of material properties, so it is difficult to establish a direct relation between the material properties and the structural and overall final weight. Interaction among different failure modes, design constraints, manufacturability and other factors make the relation between material properties and weight difficult to analyze. For instance, if a thin walled structure is sized with a minimum manufacturable thickness, whatever improvement of the Young's module of the material will not have any impact in the structure weight.
Therefore, before launching a campaign for any material improvement a previous analysis would be desirable to avoid spending a lot of money without obtaining the expected weight reduction. However a detailed analysis of the structure for each possible configuration of the material is so expensive than sometimes the investment becomes unacceptable. Consequently the decisions regarding material improvement programs not always are supported by technical reasons.
The present invention is intended to solve this drawback.